The evidence question
Do You Make Different Decisions in Your Second Language?
Research suggests that the language you use can shift some decisions — but not because a second language simply makes you more rational.
A question worth asking.
09 sources, open to exploreIn this article 15 sections
Imagine being offered the same gamble twice.
Nothing about the odds changes. Nothing about the money changes. The only difference is that one version is written in your first language and the other in a language you learned later.
Should the language matter?
Intuitively, no. If you understand both versions, the information is the same.
Yet a surprisingly large body of bilingualism research suggests that some judgments and choices can shift with the language in which they are made.
The phenomenon is usually called the foreign-language effect.
It is real enough to survive meta-analysis. It is also much easier to exaggerate than headlines make it seem.
Yes, using a second or foreign language can change some decisions on average — especially in experimental tasks involving framing, risk, and moral conflict. But the effect is generally small, varies by task and language context, and does not mean that your second language turns you into a more rational person.
Two major meta-analyses found reliable language-related differences across decision-making experiments. In one synthesis of 91 experiments involving 13,886 participants, people working in a foreign language were somewhat less likely to make the response classified as emotionally driven or biased in the experimental tasks.
That finding needs an important translation into ordinary life:
language can change the psychological context of a decision without changing the facts of the decision.
Exactly why that happens is still debated.
The puzzle begins with framing
One of the classic demonstrations uses a problem in which the same outcomes are described either as lives saved or lives lost.
Logically, equivalent outcomes should produce equivalent preferences.
Psychologically, they often do not.
People tend to respond differently depending on whether an option is framed as a gain or a loss. This is the framing effect, a famous example of how presentation can influence choice even when the underlying quantities are equivalent.
In 2012, Boaz Keysar, Sayuri Hayakawa and Sun Gyu An asked bilingual participants to make such decisions in either their native or foreign language.
Across four experiments, the familiar framing bias was reduced when participants used the foreign language.
That was strange for two reasons.
First, the participants could understand the foreign-language version. The informational content was not supposed to change.
Second, using a less automatic language might seem as though it should make reasoning worse, not protect people from a bias.
Instead, the language itself appeared to alter how the choice was processed.
Same numbers, different psychological distance
Suppose a company must choose between two plans after a serious failure.
One version says:
Plan A: 200 jobs will be saved.
Another mathematically equivalent version emphasizes how many jobs will be lost.
If you react differently to the two descriptions, the numbers have not changed.
What changed is the frame through which you encountered them.
Now add a second layer.
Imagine reading the problem in English when English is a language you learned mostly at school, through media, and later at work.
The words may be perfectly understandable while still carrying a different emotional and experiential history from their equivalents in your first language.
That creates a useful distinction:
understanding the same proposition does not guarantee experiencing it in exactly the same way.
This is one reason the foreign-language effect became so interesting. It suggests that language is not always a transparent container carrying facts from sentence to mind.
The container can become part of the context.
The effect survived much larger tests
A single surprising experiment can be a curiosity. A literature matters more when results can be combined across studies.
Two meta-analyses published in 2021 and 2022 examined the foreign-language effect across decision-making research.
Circi and colleagues synthesized 47 experiments from 17 studies. Their analysis found language-related effects in both moral decision-making and risk-aversion tasks. In the moral studies, foreign-language use was associated with greater willingness to accept harm when doing so maximized the stated outcome; in the risk studies, it was associated with reduced risk aversion.
A later meta-analysis by Del Maschio and colleagues included 91 experiments and 13,886 participants across decision problems and moral dilemmas.
It found a small but statistically reliable overall foreign-language effect: compared with participants using their native language, those using a foreign language were somewhat more likely to make the response the researchers classified as unbiased in decision problems or utilitarian in moral dilemmas.
91 experiments, 13,886 participants — and still a small effect
The larger meta-analysis pooled results from 6,928 participants tested in their first language and 6,958 tested in a second language.
That scale is useful because it changes the question from:
Can language ever affect a decision?
to:
Across many experiments, is there a repeatable shift?
The answer was yes.
But repeatable does not mean large.
The pooled effect was small, and the literature is heavily shaped by particular laboratory tasks. In the 91-experiment synthesis, most experiments involved moral dilemmas, most presented the task in writing, and English was the second language in a large share of the experiments.
So the evidence supports a real phenomenon much more strongly than it supports a sweeping rule about every bilingual decision.
Moral dilemmas make the effect especially visible
Another major branch of the literature asks people to judge difficult moral trade-offs.
The famous Footbridge dilemma asks whether it is acceptable to push one person to their death if doing so would stop a runaway trolley and save five others.
In 2014, Albert Costa and colleagues tested versions of moral dilemmas across several populations.
Participants using a foreign language were more willing, on average, to choose the action that sacrificed one person to save a larger number.
That result is often summarized as:
foreign language makes people more utilitarian.
But even that phrase needs care.
A choice in one stylized dilemma is not a personality test for utilitarianism. It tells us how language affected responses under a particular conflict between an emotionally aversive action and an outcome-maximizing result.
One explanation: you may feel the problem differently
Why would language change a moral judgment when the scenario is understood?
One influential explanation is reduced emotional resonance.
A later-learned language is often acquired in classrooms, textbooks, media, and relatively controlled environments. A first language is more likely to be entangled with childhood, family, punishment, affection, embarrassment, conflict, and thousands of emotionally significant interactions.
That difference can matter even when semantic understanding is excellent.
Research on bilingual emotion has found that emotionally charged expressions can produce different subjective and physiological responses across a bilingual's languages. The separate VocaNum article Why Do Swear Words Feel Weaker in Your Second Language? explores that evidence directly.
Hayakawa and colleagues tested the emotional-distance explanation in six moral-judgment experiments using a method designed to separate two possible mechanisms.
Was foreign-language use increasing deliberate, outcome-maximizing reasoning?
Or was it reducing the pull of the emotional prohibition against harmful action?
Their results favored the second account: foreign-language use reduced deontological responding without increasing utilitarian responding.
That distinction matters.
It is not necessarily:
less emotion → more careful reasoning → better answer
It may instead be:
weaker emotional response → one consideration carries less weight → choice shifts
Myth: thinking in English makes you more rational
Myth: If your second language reduces certain biases, you should use it whenever you need to make an important rational decision.
Reality: The evidence does not establish a general cognitive upgrade.
Some experiments find reduced framing, loss aversion, or emotionally driven responding. But decision quality is not one single variable, and reducing one influence can expose another weakness.
For example, research on logical reasoning has found that people reasoning in a foreign language can show lower accuracy and weaker sensitivity to logical conflict under some conditions.
A second language can require more processing effort. Vocabulary may be less automatic. Subtle implications may be easier to miss. Emotion can be useful information rather than noise. Social and moral norms can also be part of what a competent decision-maker should consider.
So “less biased in one laboratory paradigm” cannot safely be translated into “smarter decisions overall.”
The label “foreign-language effect” may itself be too simple
Here is one of the most interesting complications.
If the effect comes from a foreign language being learned later and feeling emotionally weaker, what should happen in people who speak two native languages?
Miozzo and colleagues tested proficient Italian–Venetian and Italian–Bergamasque bilinguals.
Venetian and Bergamasque were not classroom foreign languages. Participants were native, proficient bilinguals, and the researchers did not find the simple emotional-intensity difference that a straightforward emotional-distance account would predict.
Yet language-related differences appeared in both the Asian Disease framing problem and the Footbridge dilemma.
The researchers proposed that the contexts in which languages are used may matter.
Italian was associated with broader and more formal contexts; the regional languages were used more heavily in households and informal social circles.
That result changes the mental model.
Instead of:
native language vs foreign language
we may sometimes need:
language + learning history + social context + emotional history
Do not turn an average experimental effect into a personal decision hack
It is tempting to convert this research into advice:
Negotiating a salary? Switch to English.
Making an investment? Think in your second language.
Facing a moral conflict? Translate it.
The evidence is not strong enough for those prescriptions.
Most studies do not follow people through high-stakes real-world decisions. Experimental tasks simplify choices so researchers can isolate variables. A trolley dilemma, hypothetical gamble, or framed disease problem is not the same environment as choosing a medical treatment, ending a relationship, signing a contract, or investing your savings.
The language effect can also depend on the languages involved and how they are used.
Dylman and Champoux-Larsson, for example, found the effect with some Swedish bilingual language pairings but not others. Their experiments suggested that linguistic similarity and cultural influence may constrain when the effect appears.
The meta-analytic evidence tells us that language can systematically matter.
It does not give us a universal switch for improving decisions.
Proficiency is not the whole explanation either
You might expect the effect to disappear as someone becomes highly proficient.
The evidence is less tidy.
Both major meta-analyses examined proficiency as a possible moderator and did not find a simple pattern in which greater second-language proficiency reliably erased the effect.
That does not prove proficiency is irrelevant. Measures of proficiency varied across studies, often relied on self-report, and bilingual experience contains more dimensions than a single score.
A person can be highly proficient in English and still use it mainly for work.
Another can have similar test proficiency but use English with a partner, close friends, and family every day.
Those languages occupy different lives.
This connects with another VocaNum article, Do You Become a Different Person When You Speak Another Language?, which examines how switching languages can also switch cultural, interpersonal, and autobiographical contexts.
For decision-making, that broader context may be part of the mechanism rather than background noise.
What should a language learner actually take from this?
The most useful lesson is not a trick for making decisions.
It is a lesson about what it means to know a language.
Advanced language knowledge is not merely the ability to map:
sentence → dictionary meaning
A language also develops emotional associations, social expectations, automatic reactions, memories, norms, and patterns of use.
Two sentences can be semantically equivalent while entering the mind through partly different histories.
That helps explain several experiences familiar to bilinguals:
- a swear word can feel weaker even when you know exactly how offensive it is;
- an embarrassing topic can be easier to discuss in one language;
- your personality can feel slightly different across language contexts;
- and some choices can shift even when the factual information stays constant.
These are not separate magical powers of bilingualism.
They are clues that meaning is richer than translation equivalence.
A useful experiment you can try — without pretending it improves the decision
The next time you face a low-stakes choice, write the reasoning in both languages.
Do not ask which language gives the “correct” answer.
Instead notice what changes.
Does one version feel more emotionally intense?
Do different words make a consequence feel more concrete?
Does one language make you focus more on social expectations?
Do you become slower because retrieving the right phrasing takes effort?
Do different memories or examples come to mind?
This is not a scientifically validated decision technique. It is a way to observe your own bilingual experience.
If the two versions feel different, the research gives you several plausible reasons why.
If they feel identical, that is perfectly compatible with the research too: these are average effects with substantial variation, not a rule every bilingual must experience.
The language of a decision can become part of the decision
A second language does not merely replace one set of words with another.
In experiments involving framing, risk, and moral conflict, changing language can produce small but repeatable shifts in choice. Large meta-analyses suggest the phenomenon is not just an isolated laboratory curiosity.
But the strongest version of the story — “foreign languages make people rational” — is not supported.
Reduced emotional resonance may explain part of the effect. Cognitive effort may matter. The social contexts attached to each language may matter too. And in some tasks, operating in a foreign language can impair rather than improve reasoning.
The deeper lesson is more interesting than the productivity hack:
Two languages can describe the same choice while making that choice psychologically different.
Learning another language therefore gives you more than another way to encode information.
Over time, it gives information another history through which to reach you.
Sources and further reading
- Keysar, Hayakawa & An (2012) — The foreign-language effect: Thinking in a foreign tongue reduces decision biases
- Costa et al. (2014) — Your morals depend on language
- Hayakawa et al. (2017) — Thinking more or feeling less? Explaining the foreign-language effect on moral judgment
- Hadjichristidis, Geipel & Savadori (2019) — The influence of native language in shaping judgment and choice
- Miozzo et al. (2020) — Foreign language effect in decision-making: How foreign is it?
- Dylman & Champoux-Larsson (2020) — It's (not) all Greek to me: Boundaries of the foreign language effect
- Białek et al. (2020) — Thinking in a foreign language distorts allocation of cognitive effort: Evidence from reasoning
- Circi et al. (2021) — The foreign language effect on decision-making: A meta-analysis
- Del Maschio et al. (2022) — Decision-making depends on language: A meta-analysis of the Foreign Language Effect